Abstract: In the history of physics, J D van der Waals pioneered studies on the fundamental properties of the gas－liquid system, establishing the first equation of state which describes not only gases and liquids but also phase transition and critical phenomena. His theoretical achievements and scientific method had profound influence on the development of thermodynamics, statistical mechanics and low temperature physics. We present an overview of the van der Waals equation, including its historical background and scientific significance and deficiency, and discuss its influence on modern physics.